I don't think you want a device driver for a USB device.
[3] is a DRVR driver for an emulated storage device? DRVR drivers are 68K.
[4] is more disk driver stuff. Just a bunch of low memory globals equates. It's a lisp binding for classic Mac OS API. Like how Apple has headers for 68K assembly, Pascal, and C.
Is the PS3 sixaxis a HID class USB device? Test that by connecting it to a Mac. Use USB Prober.app to dump info about the device. It will list interfaces of the USB device. If the USB device supports HID, then it will also have a HID descriptor. There's versions of USB Prober that work with Tiger to Monterey and probably beyond.
What does Virtual Game Station require for an input device? I think HID should be sufficient, unless they chose proprietary devices. Does it support any ADB devices? ADB devices are not HID. I suppose one could make a HID driver for an ADB device - I've done that for Mac OS X - not sure if that's possible for Mac OS 9.
There's a USB DDK for Mac OS 9 (1.5.5f1, 1.5.9f1). It also contains a classic version of USB Prober.
Since Virtual Game Station is PowerPC only, and USB doesn't exist for 68K Macs, you probably want your driver to be PowerPC also.